'use strict';

var fs = require('fs');

function addControllers(router, dir) {
    var files = fs.readdirSync(__dirname + `/${dir}`);

    var js_files = files.filter((f) => {
        return f.endsWith('.js');
    });

    // 处理每个js文件
    for (var f of js_files) {
        console.log('process controller: ' + f);

        // 导入js
        let mapping = require(__dirname + `/${dir}/` + f);

        addMapping(router, mapping);
    }
}

function addMapping(router, mapping) {
    for (var url in mapping) {
        if (url.startsWith('GET ')) {
            var path = url.substring(4);
            router.get(path, mapping[url]);
            console.log(`register URL mapping: GET ${path}`);
        } else if (url.startsWith('POST ')) {
            var path = url.substring(5);
            router.post(path, mapping[url]);
            console.log(`register URL mapping: POST ${path}`);
        } else if (url.startsWith('PUT ')) {
            var path = url.substring(4);
            router.put(path, mapping[url]);
            console.log(`register URL mapping: PUT ${path}`);
        } else if (url.startsWith('DELETE ')) {
            var path = url.substring(7);
            router.del(path, mapping[url]);
            console.log(`register URL mapping: DELETE ${path}`);
        } else {
            console.log(`invalid URL: ${url}`);
        }
    }
}

module.exports = function (dir) {
    let
        controllers_dir = dir || 'controllers',// 如果不传参数，扫描目录默认为'controllers'
        router = require('koa-router')();
    addControllers(router, controllers_dir);

    return router.routes();
}